Fragmentation Analysis in Open Cast Blasting
IR@CIMFR: CSIR-Central Institute of Mining and Fuel Research, Dhanbad
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| Title |
Fragmentation Analysis in Open Cast Blasting
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| Creator |
Raina, A.K.
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| Subject |
Blasting
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| Description |
Blasting is an intricate process with multitude of parameters determining its outcome. The requirements of a mine further add to its complexity. Blasting in itself can’s be seen in isolation as it is a part of system generally referred to as Mine-Mill Fragmentation system. This system takes into account all unit operations related to transformation of in-situ rock into the mill product. The process of breakage in blasting is loosely referred to as fragmentation. However, fragmentation can be defined as the distribution of size of fragments produced during blasting. The subject has been a subject of debate over several decades. The fragmentation is characterized by two major parameters viz. the mean (K50) or Median (M50) fragment size and the slope or curvature of fragment size distribution defined by the characteristic size (Xc – normally the 63.2% passing size) and the uniformity – denoted by Uniformity Index (n). There have been attempts to predict the fragmentation in blasting. These include direct empirical models based on actual field data and mathematical models that represent the distribution. In order to predict the fragmentation an appreciation of this distribution is essential. However, the distributions known as Rosin-Rammler or Weibull distributions have their own limitation. These tend to be biased towards the fines. So, a fines correction is always required to be carried over. Recent developments of Swebrec function has tried to address the problems. In addition to the distribution function the measurement of fragmentation in itself is a difficult proposition. The conventional methods have not yielded any better results or these are quite cumbersome – like sieve analysis and are practically impossible. Digital image Analysis Technique (DIAT) has been developed to assist in this procedure and there are several such software systems in vogue. However, this type of analysis has its own constraints owing to different aspects like imaging, 2D-3D unfolding model and sampling. Several attempts are being made to address these problems. This article attempts to summarize the concepts, developments and the future trends of the fragmentation analysis.
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| Publisher |
IME Publication Bhubaneswar
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| Date |
2009-12
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| Type |
Article
PeerReviewed |
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| Identifier |
Raina, A.K. (2009) Fragmentation Analysis in Open Cast Blasting. Indian Mining & Engineering Journal , 48 (12). pp. 20-13. ISSN 0019-5944
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| Relation |
http://cimfr.csircentral.net/415/
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